"""Guards that stop one bad YouTube answer from cascading: the playlist-push circuit breaker."""
from app.sync.playlists import _Breaker


class TestBreaker:
    def test_open_until_the_limit_is_reached(self):
        b = _Breaker(limit=3)
        for _ in range(2):
            b.hit(False)
            assert b.open()
        b.hit(False)
        assert not b.open() and b.tripped

    def test_a_success_re_arms_the_streak(self):
        b = _Breaker(limit=3)
        b.hit(False)
        b.hit(False)
        b.hit(True)  # one write went through — this isn't an account-wide failure
        b.hit(False)
        b.hit(False)
        assert b.open()

    def test_stays_tripped_once_tripped(self):
        b = _Breaker(limit=2)
        b.hit(False)
        b.hit(False)
        b.hit(True)
        assert not b.open()